From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hanjun Guo <hanjun.guo@linaro.org>
Subject: Re: [PATCH v9 05/21] ARM64 / ACPI: Get RSDP and ACPI boot-time tables
Date: Tue, 10 Mar 2015 19:36:00 +0800
Message-ID: <54FED720.8080401@linaro.org>
References: <1424853601-6675-1-git-send-email-hanjun.guo@linaro.org> <1424853601-6675-6-git-send-email-hanjun.guo@linaro.org> <20150305185117.GA17415@e102568-lin.cambridge.arm.com> <54FEA4CC.8090000@linaro.org> <20150310111931.GU4278@bivouac.eciton.net>
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To: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Catalin Marinas <Catalin.Marinas@arm.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Will Deacon <Will.Deacon@arm.com>, Olof Johansson <olof@lixom.net>, "grant.likely@linaro.org" <grant.likely@linaro.org>, Arnd Bergmann <arnd@arndb.de>, Mark Rutland <Mark.Rutland@arm.com>, "graeme.gregory@linaro.org" <graeme.gregory@linaro.org>, Sudeep Holla <Sudeep.Holla@arm.com>, "jcm@redhat.com" <jcm@redhat.com>, Marc Zyngier <Marc.Zyngier@arm.com>, Mark Brown <broonie@kernel.org>, Robert Richter <rric@kernel.org>, Timur Tabi <timur@codeaurora.org>, Ashwin Chaugule <ashwinc@codeaurora.org>, "suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>, "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "linux-kernel@vger.kernel.org" <linux-kern>
List-Id: linux-acpi@vger.kernel.org

On 2015=E5=B9=B403=E6=9C=8810=E6=97=A5 19:19, Leif Lindholm wrote:
> On Tue, Mar 10, 2015 at 04:01:16PM +0800, Hanjun Guo wrote:
>>>> index 0000000..f052e7a
>>>> --- /dev/null
>>>> +++ b/arch/arm64/kernel/acpi.c
>>>> @@ -0,0 +1,101 @@
>>>> +/*
>>>> + *  ARM64 Specific Low-Level ACPI Boot Support
>>>> + *
>>>> + *  Copyright (C) 2013-2014, Linaro Ltd.
>>>> + *	Author: Al Stone <al.stone@linaro.org>
>>>> + *	Author: Graeme Gregory <graeme.gregory@linaro.org>
>>>> + *	Author: Hanjun Guo <hanjun.guo@linaro.org>
>>>> + *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>>> + *	Author: Naresh Bhat <naresh.bhat@linaro.org>
>>>> + *
>>>> + *  This program is free software; you can redistribute it and/or=
 modify
>>>> + *  it under the terms of the GNU General Public License version =
2 as
>>>> + *  published by the Free Software Foundation.
>>>> + */
>>>> +
>>>> +#define pr_fmt(fmt) "ACPI: " fmt
>>>> +
>>>> +#include <linux/acpi.h>
>>>> +#include <linux/bootmem.h>
>>>> +#include <linux/cpumask.h>
>>>> +#include <linux/init.h>
>>>> +#include <linux/irq.h>
>>>> +#include <linux/irqdomain.h>
>>>> +#include <linux/memblock.h>
>>>> +#include <linux/smp.h>
>>>> +
>>>> +int acpi_noirq;			/* skip ACPI IRQ initialization */
>>>> +int acpi_disabled;
>>>> +EXPORT_SYMBOL(acpi_disabled);
>>>> +
>>>> +int acpi_pci_disabled;		/* skip ACPI PCI scan and IRQ initializat=
ion */
>>>> +EXPORT_SYMBOL(acpi_pci_disabled);
>>>> +
>>>> +/*
>>>> + * __acpi_map_table() will be called before page_init(), so early=
_ioremap()
>>>> + * or early_memremap() should be called here to for ACPI table ma=
pping.
>>>> + */
>>>> +char *__init __acpi_map_table(unsigned long phys, unsigned long s=
ize)
>>>> +{
>>>> +	if (!phys || !size)
>>>
>>> Is there a reason to rule out physical address 0x0 ?
>>
>> No particular reasons, unless some arch/firmware limits, I'm
>> not sure if we need this check (x86 needs it), I'm CC Leif
>> to confirm.
>
> Nothing in UEFI explicitly bans using physical address 0 for anything=
,
> and nothing in the architecture reserves it. So I don't think this
> check is necessary.

Thanks for the confirmation, will remove the !phys check.

Hanjun